Retro-King Amps Plexi 50 Head

This is a follow-up review on the Retro King Plexi 50 with the Brown Sound Mod. What was formerly the "Normal" channel on the amp is now equipped with a gain control. A master volume was also installed on the amp which governs both channels. Since I am not too "Tech Savvy", I'll leave it to the RK website to provide the specifics. The end result is an amp that still retains its classic "plexiness" while providing an increase in tonal versatility.

Outstanding! This modification allows me to push the power tubes creating a rich and pleasing overdrive while not shaking the foundations of my house. Even at these lower volumes, the rich and chimey quality of the plexi stands out. Notes are beautifully articulated. The guitar cuts through the band mix particularly well. I found that I had very little need for my stomp boxes when I played it out for the first time 3 nights ago. Half way through the evening, I found the sweet spot for my taste to be the gain channel with the main volume and gain both on 7, and the master volume at about 2 or 3. When I would step up for a guitar solo, I simply stepped on my boost pedal. When I wanted to clean up, I just rolled the volume down on my PRS custom 22. I Played the amp through a pair of Vintage 30 speakers. I would characterize the overall sound of the amp as muscular with a singing sustain. My bandmates were happy with me as well since the volume was not overwhelming, but the tone actually enhanced our overall sound. This amp fits the bill for me in so many ways. My band is a classic rock cover band...we play alot of Tom Petty, Black Crowes, Led Zepplin, ZZ Top... Now I have a more hard hitting and authentic sound than I ever did before. While there may be some Plexi Purists who would disapprove of something like this, the practical truth is that I would never be able to get this type of tone from this amp at low volumes in the small venues that we play. I've tried it with various effects boxes and a power break. At the end of the day however, this mod gave me exactly what I was looking for.

I fully expect it to last for a long time...

Excellent. Retro King Founder Chuck Dean does a great job period.

While I dont play like EVH, the Brown Sound mod makes a great amp like this sensational sounding and gives my great tonal flexibility.

You know...standard Marshall plexi panel 4-input and usual tone array. This particular amp has a variable feedback/gain control to control the negative feedback to the output tubes and it has the tube rectifier 5AR4/GZ34. Both of which I would definitely suggest getting!

I've played a few genuine 60's plexi panel amps in my day...and none of them sounded as good as this amp sounds. The originals either had transformer issues or bad cap issues or excessive noise too much bright/barky top end etc...NOT THIS AMP! This guy gets it right...right down to the smooth and creamy spongy sag as you turn up the volume. I jump the high 2 input with the low 1 input and then plug into the high 1 input. I run both low and high volumes around '7' (2 o'clock) and plug into a Marshall 60's bottom cab with vintage greenbacks (greenbacks are a must for this amp)My pedalboard is very quiet as is the amp (even at this volume....almost SILENT) using my custom shop strat with Lollar pick-ups the amp gets a real Richie Blackmore kinda thing going (think 'Burn' or 'Highway Star') I mean it sounds EXACT dead on...the notes are controlled by how hard you pick or strum and the amp cleans up VERY NICELY when the guitar volume is rolled back (doesn't 'thin out' BIG PLUS!!!) This amp is very musical and as someone here has already stated, even when dimed it isn't hurting your ears or causing 'ear fatigue' as the new Marshall re-issue amps absolutely SUCK when dimed...note definition is still there and very controllable even with the excessive gain...this amp distorts beautifully and musically with the vintage greenbacks...just awesome! My humbucking guitars can reach into heavy metal territory easily...but, I'm more a blues/rock guy. This is the best Marshall amp I've played clone or otherwise.

Wiring and workmanship all look good...quality components...should last quite a while...keep fresh tubes going and no worries.

Accessible and helpful.

If your looking for a heavy metal high gain amp there are better choices...but, if you know what a Marshall plexi panel sounds like...a GOOD ONE, then this is an excellent choice for great plexi tone.

Made in 2006. All tube, one channel guitar amp comparable to the Marshall 50 watt Plexi that was the mainstay of rock duing the late 60's/early 70's. I play guitar in a classic rock cover band. I find that this amp is very versitile depending on what pedals you place in front of it. This amp is loud. I use a hotplate to achieve a nice overdriven tone without destroying my hearing.

I have yet to find a sound that I cannot get out of this amp. The amp distorts nicely at higher volumes and remains clean at lower volumes. I run it through a 2x12 cabinet with 1 Vintage 30 and 1 G12H-30 speaker. What strikes me most about this amp is how the characteristics of each guitar shines through. I play a PRS Custom 22, and a 1979 Gibson Les Paul Custom. The "Strat-Like" qualities of the PRS are very articulate, while the LP is big and chunky. I can play any of the classics with the right stomp box, and with my Boss multi effects system, I can easlily get into the more modern rock sounds. Depending on what pedals you use, you can go from Zepplin and Black Sabbath into Van Halen and Randy Rhoads territory. Lead riffs absolutely sing! Sustains forever..I absolutely love it! I play in small clubs and bars. Since it is so loud, I don't need to turn it up too high, therefore noise is no problem. The hotplate has a noise gate as well.

3 months. So far so good. I fully expect it to be reliable...I will assign a rating after one year.

Chuck Dean is the creator of these fine amps. He is completely accessible via telephone or e-mail. He hand wires each of these amps and stands behind his work. Whenever I have had a question, he has been very prompt in his responses. He has offered great suggestions regarding pedals, cabinets and other ideas on how to create great sounds from this amp. I like that I can go directly to the person that built the amp for advice..absolute integrity!

Been playing for 30+ years. I'm a weekend warrior, but passionate about playing. I live in California. I liked the fact that for 20-30% less than what I would have paid for an assembly line Marshall Plexi, I was able to buy a hand wired Plexi directly from the individual that built it in upstate NY instead of dealing with some overseas corporate lacky. If I were to lose this amp, I would replace it immediately...I absolutely love it! As I write this review, I'm saving my mad money for the 18 watt combo..great work Chuck!

2005 Custom built replica of a 1960s Marshall 50 Watt Plexi head
Features are:

"Plexi 50"2 channel 4 inputs (high & low)
High treble & normal channels
2 Volume, Treble, Mid, Bass and presence

2 Matched Svetlana EL34 power tubes
3 JJ 12AX7 preamp tubes
1 GZ34 tube rectifier
Heyboer transformers (120/240 volt primary)

Output Tranny has correct 3.4 k primary
4, 8 or 16 ohm selector
Two speaker outputs
Negative feedback control (47 to 100k)

Plexi panels
Original 50 watt Plexi specs
Mallory caps allen bradley carbon comp resistors
Aluminum chassis
Hand wired point to point (Teflon wire)
Baltic birch cabinet (black Levant Tolex)

This head is a classic rocker designed for anything from club gigs to stadiums. It is mainly geared toward classic rock, blues etc., but can achieve a variety of tones thanks to the negative feedback control that boosts gain.

The predominant feature of the Plexi 50 is its great musicality and beautiful tone. The high treble channel is not as bright as those found on some Marshalls nor the nornmal channel as deep. The bass is tight on both channels and the frequency response very balanced. The tone is of course affected by the speaker cabinets. My set up is through an 8 ohm 80 Watt Dr Z 2x12 closed back birch cabinet mounted with vintage Celsetions. The lower the wattacge, the more break up.

Depending on volume and eq settings the Plexi 50 can achieve a remarkable variety of tones. Easily accessible are AC/DC, Led Zeppelin, Ritchie Blackmore and Hendrix type sounds as this amp is very much in the same vein as the equipment used by these players. Also achievable with varied EQ settings are Eric Johnson, early Mahavishnu and DiMeola type sounds. Thus the amp ranges into fusion territory. While not specifically built for the heavily saturated distortions of modern rock/Metal, the amp is versatile enough to be used for this music with the appropriate pedals. In addition, the Plexi 50 is very "alive", touch reponsive and sensitive. Turn down pickups and it cleans up beautifully. Play harder and it distorts more.

My guitars include a Les Paul Standard with 490R humbucker in the neck position, and burstbucker at the bridge, and an Eric Johnson signature strat. Pedalboard includes a Fulltone 70s Fuzz, Chandler Tube Driver, Boss DS- 1, Boss DD-2, Electro-Harmonix Memory Man and TC Electronics Chorus. The amp interacts beautifully with the various pedals, but is more noisy as all pedals are in front of signal chain- (no effects loop here, of course). The analog and digital delays come out sounding beautiful, even with volume at ten-(think Eric Johnson's wet sound on Cliffs of Dover).

I have only had the amp for 1 month, but its tight construction and simple design lead me to believe that it will last as long as many Marshalls built 40 years back.

Charles Dean, maker of Retro-King amps is responsive, understanding easy to work with and easily accessible. Try getting this kind of service from Marshall in England or makers of other similar amps.

Amp was built in the exact time specified, delivered as expected and works perfectly.

I am a guitarist of some 20+ years experience and currently play in a classic/modern rock cover band (as a hobby) that also does some originals. We cover anything from ZZ Top, Cheap Trick etc. to Nine Inch Nails, Nickelback, even Pat Benatar. Other amps are a Guytron GT-100 head, 74 Silverface Vibrolux reverb, 20th anniversary Hughes and Kettner Combo and a Polytone Mini Brute IV for Jazz work.

One essential to remember for guitarists looking for that famed Marshall sound. The Plexi 50 are priced at half of the new hand-wired Marshall equivalents and half of the Blockhead and Mojave amps. I have auditioned the latter two and like the Retro-King better.

2005 custom built 2 channel 50 Watt head with 4 inputs (high & low)
High treble & normal channels
2 Volume, Treble, Mid, Bass and presence

2 Matched Svetlana EL34 power tubes
3 JJ 12AX7 preamp tubes
1 GZ34 tube rectifier
Heyboer transformers (120/240 volt primary)


4, 8 or 16 ohm selector
Two speaker outputs
Negative feedback control (47 to 100k)

Plexi panels
Original 50 watt Plexi specs
Mallory caps allen bradley carbon comp resistors
Aluminum chassis
Hand wired point to point (Teflon wire)
Baltic birch cabinet (black Levant Tolex)

The Plexi 50 is a handbuilt, hand wired replica of a late 60s Marshall 50 Watt Plexi head as the name indicates. The features and controls duplicate those of a vintage Marshall with the exception of the negative feedback knob located on the rear panel that allows the user to dial in additional gain. There are no excess features on this amplifier and using it could not be more straight forward.
I rate the amplifier a 10 in this category simply because no one would reasonably expect it to be appropriate for a quiet jazz combo, but for musical categories such as classic rock (obviously), southern rock, blues, fusion etc. the amp is ideal.

The single best word describe this gem of an amplifier is "musical". It is simply hard to get a bad sound out of it regardless of eq settings and volume.

The Plexi 50 is ideally geared to the musician seeking authentic vintage tones. It faithfully replicates the sound of the best vintage Marshalls of its kind without the price tag or hassle associated with gear that is now reaching its fourth decade in age. More importantly, the amplifier, even on the high treble channel does not have any of the excessive brightness found in some vintage Marshalls and found in virtually all the re-issues coming out of the Marshall factory today. The Plexi's produces smooth distortion and starts to break up nicely at settings of around 4, depending on the guitar used. Even at 10, the volume in my own living room did not sound oppressive because the sound is so musical, and, make no mistake about it, this is a loud amp.

The amp's circuitry is also extremely quiet, probably because of the quality of its components. Once again, even when "dimed out" there is no excessive noise.

I tested the Plexi with an array of effects including a Chandler Tube Driver, a Fulltone 70's fuzz, an Electro- Harmonix Memory Man analog delay re-issue, and a Boss DS-1 distortion using an Eric Johnson signature Strat and a late model Les Paul standard with burstbucker pickups. I played through a Dr Z 80 watt closed back 2 x 12 Cabinet loaded with Celestions. I was able to get a multitude of sounds ranging from typical Hendrix tones (not surprisingly) to classic Eric Johnson lead and dirty rhythm sounds (using the fuzz and tube driver), to Santana-like sustains, and Mahavishnu style tones (think Dawn on "the Innner Mounting Flame" album). The plexi nails a variety of blues sounds effortlessly without any effects.

The amp interfaces very well with all these effects including the Memory Man. Rolling off the guitars volume knob, even with the amp at high volumes, generates typical Marshall type clean tones, and the Plexi is extremely touch sensitive - the harder you play the more it breaks up.

The Plexi is not designed to produce the brutal modern distortion tones favored by today's thrash or metal-players, but this can hardly be considred a failing. Nevertheless, it remains surprisingly versatile in its scope, particularly for an amplifier whose original design features go back to a bygone era.

I have only acquired the amplifier recently and thus can not give an accurate opinion of reliability, but by all indications it is built like a tank, and with reasonable retubing should outlive its owner.

Chuck Dean of Retro King is responsive, knowledgable and easy to deal with. I filled out the order form online, got a call back within minutes, ordered the amp, and a month later it was delivered no hassles.

When the amp arrived, I called Chuck becasue a .5 amp fuse had broken in transit and her recommended I replace it with a 1 amp.

Chuck is a working musician of 30 years experience and is tops in the customer service department- easy to get a hold of too.

My overall rating for this amp is 10, with the caveat that I have only received it recently and cannot absolutely vouch for its reliability, though I have no reaqson to think it won't outlast me.

I compared the amplifier with a number of amps that purport to do the same thing, including the Blockhead Marshall replicas, Mojave amps, and hand-wired Marshall reissues that have recently emerged on the market. Retro-King beats them all at a fraction of the cost, and remember all of these other amplifiers are of extremely high quality, though close to double the price of the Retro King. Also, the waiting list for the 100 Watt Marshall HW is approximately 3 months.